| 1. |
- Browaeys, Hilde, et al.
(författare)
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The histological evaluation of osseointegration of surface enhanced microimplants immediately loaded in conjunction with sinuslifting in humans.
- 2013
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Ingår i: Clinical oral implants research. - : Wiley. - 1600-0501 .- 0905-7161. ; 24:1, s. 36-44
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim was to investigate histomorphometrically whether or not implant surface nanotopography improves the bone response under immediate loading simultaneous to sinus grafting. MATERIALS AND METHODS: Dual acid-etched titanium microimplants with/without crystalline surface deposition of calcium phosphate particles were placed in bilateral sinuslift areas grafted with a mixture of iliac crest bone and BioOss. Surface topography of microimplants was characterized using interferometry. Loaded microimplants (MsL) were immobilized in a provisional bridge supported by four normal size implants. Some patients had unloaded microimplants as controls (MsU). Biopsies were trephined after 2 or 4months and histomorphometric analysis of bone area (BA) and bone-to-implant contact (BC) was performed. Nonparametric methods for dependent data were used to compare effect of surface modification, and healing time (2 vs. 4months). RESULTS: A total of 53 biopsies were available from 13 patients. A total of 4/28 and 1/11 MsL failed after resp. 2 and 4months vs. 0/6 and 1/5 MsU. Many loaded biopsies were damaged at the apical portion and showed no bone adhesion. MsL decreased in BA from coronal to apical from 2 to 4months; Coronal>Middle (P=0.047), Coronal>Apical (P<0.001) and Middle>Apical (P<0.001). This gradual decrease was not observed for BC; CoronalApical (P<0.001). Only the middle part showed significant bone contact after 2months. For MsL there was no statistically significant difference between surface or time indicating that improvement of osseointegration over time due to maturation of the graft was poor. The MsU did not show any difference between Osseotite and Nanotite for BIC and BA (P>0.05) but doubled both their BA and BIC (P<0.05) between 2 and 4months. CONCLUSIONS: Osseointegration in sinus-grafted bone mixed with BioOss was poor irrespective of healing time or nanotopographical surface modification. The apex of MsL showed minimal bone contact suggesting that the graft does not add to the loading capacity. Surface enhancement was not beneficial despite the enlarged surface area. Overloading, most critical coronally of an implant, increases risks for implant failure and jeopardizes bone healing especially under immediate loading conditions with high load.
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| 2. |
- Ivarsson, Stefan, et al.
(författare)
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Improved oscillator strengths and wavelengths for Os I and Ir I, and new results on early r-process nucleosynthesis
- 2003
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 409:3, s. 1141-1149
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Tidskriftsartikel (refereegranskat)abstract
- The radioactive decay of 238U and 232Th has recently been used to determine ages for some of the oldest stars in the Universe. This has highlighted the need for accurate observational constraints on production models for the heaviest r-process elements which might serve as stable references, notably osmium and iridium. In order to provide a firmer basis for the observed abundances, we have performed laser-induced fluorescence measurements and Fourier Transform Spectroscopy to determine new radiative lifetimes and branching fractions for selected levels in Os I and Ir I. From these data, we determine new absolute oscillator strengths and improved wavelengths for18 Os I and 4 Ir I lines. A reanalysis of VLT spectra of CS 31082-001and new results for other stars with Os and Ir detections show that (i):the lines in the UV and lambda 4260 yield reliable Os abundances, while those at lambda lambda 4135, 4420 are heavily affected by blending; (ii): the Os and Ir abundances are identical in all the stars; (iii): the heavy-element abundances in very metal-poor stars conform closely to the scaled solar r-process pattern throughout the range 56 <= Z <= 77; and (iv): neither Os or Ir nor any lighter species are suitable as reference elements for the radioactive decay of Th and U.Based in part on observations obtained with the Very Large Telescope of the European Southern Observatory at Paranal, Chile.
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| 3. |
- Ljunggren, Stefan, 1988-, et al.
(författare)
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Modified lipoproteins in periodontitis : a link to cardiovascular disease?
- 2019
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Ingår i: Bioscience Reports. - : Portland Press. - 0144-8463 .- 1573-4935. ; 39:3
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Tidskriftsartikel (refereegranskat)abstract
- There is a strong association between periodontal disease and atherosclerotic cardiovascular disorders. A key event in the development of atherosclerosis is accumulation of modified lipoproteins within the arterial wall. We hypothesize that patients with periodontitis have an altered lipoprotein profile towards an atherogenic form. Therefore, this study aims at identifying modifications of plasma lipoproteins in periodontitis. Lipoproteins from ten female patients with periodontitis and gender- and age-matched healthy controls were isolated by density-gradient-ultracentrifugation. Proteins were separated by two-dimensional gel-electrophoresis and identified by map-matching or by nano-liquid chromatography followed by mass spectrometry. ApoA-I methionine oxidation, Oxyblot, total antioxidant capacity and a multiplex of 71 inflammation-related plasma proteins were assessed.Reduced levels of apoJ, phospholipid transfer protein, apoF, complement C3, paraoxonase 3 and increased levels of alpha-1-antichymotrypsin, apoA-II, apoC-III were found in HDL from the patients. In LDL/VLDL, the levels of apoL-1 and platelet-activating factor acetylhydrolase as well as apo-B fragments were increased. Methionine oxidation of apoA-I was increased in HDL and showed a relationship with periodontal parameters. Alpha-1 antitrypsin and alpha-2-HS glycoprotein were oxidised in LDL/VLDL and antioxidant capacity was increased in the patient group. 17 inflammation-related proteins were important for group separation with the highest discriminating proteins identified as IL-21, Fractalkine, IL-17F, IL-7, IL-1RA and IL-2.Patients with periodontitis have an altered plasma lipoprotein profile, defined by altered protein levels as well as posttranslational and other structural modifications towards an atherogenic form, which supports a role of modified plasma lipoproteins as central in the link between periodontal and cardiovascular disease (CVD).
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| 4. |
- Nilsson, Hampus, et al.
(författare)
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Experimental oscillator strengths in U II of cosmological interest
- 2002
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 381:3, s. 1090-1093
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Tidskriftsartikel (refereegranskat)abstract
- Oscillator strengths for 57 U II lines in the region 3500-6700 Åhave been derived by combining new branching fraction measurements withrecently measured lifetimes. The lines combine six upper levels withnumerous low levels having excitation energies of 0-1.5 eV. The datainclude the U II line at 3859 Å, which is used forcosmochronology.
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| 5. |
- Vervack, Valentin, et al.
(författare)
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The fracture strength and the failure mode of lithium disilicate or resin nano ceramics as a crown, overlay, or endocrown restoration on endodontically treated teeth
- 2024
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Ingår i: Journal of Esthetic and Restorative Dentistry. - : John Wiley & Sons. - 1496-4155 .- 1708-8240. ; 36:5, s. 796-803
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionDifferent materials and restorative concepts have been proposed over the years to restore endodontically treated teeth (ETT). Monolithic ceramic and composite restoration can be lute to the tooh, without the use of a post. However, little is known how the material stiffness and presence of a composite core will affect the survival and failure mode.The objective of this in-vitro study was to evaluate the fracture strength and failure mode of endodontically treated molars, restored with ceramic or hybrid composite monolithic restoration, in the presence of absence of a composite core.Materials and MethodsSixty depulped molars were restored with a lithium-disilicate (e.max CAD) or hybrid composite (Cerasmart) restoration. Both materials were used in a monolithic approach, but with 3 different designs: (a) monolithic endocrown, (b) crown with a separate composite core, and (c) overlay without core buildup or pulpal extension. Ten sound teeth were used as control group. All groups were thermocycled (10,000 cycles), subsequently loaded in a chewing simulator (100,000 cycles) and finally loaded until fracture.ResultsPeak fracture loads and failure modes were registered. No significant differences were seen between the groups in terms of fracture load. Failure modes were statistically significantly different among groups with significant correlation between restoration type and material. (p < 0.001 and p = 0.033, respectively). No group presented significantly higher fracture resistance. Although ceramic crowns and overlays presented the highest repairability, all restored ETT were within the range of the intact tooth' fracture strength.ConclusionNo restoration presented significant different fracture loads. However, the type of restoration and material choice were correlated to the fracture mode.
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